Liquid storage apparatus



Oct. 1; 1946. J. H. WIGGINS 2,408,538

LIQUID STORAGE APPARATUS Filed Dec. 24, 1945 2 Sheets-Sheet 1 v INVENTOR: JOHN H. WIGGINS.

MMW

' ATTORNEY Oct. 1, 1946. J. H. WIGGINS LIQUID STORAGE APPARATUS Filed Dec. 24, 1945 2 Sheets-Sheet 2 5 U mN N. m m Mm r g mH N% H 7 B Patented Oct. 1, 1946 ratim 's'roRaoE APPARATUS I paratu's oi' the, general type that comprises a tank or container forfholdingthe liquid, a vertically-j movable member in said tankwhich emanate a so-called; floating roof that rests u onand is sustained; byjthe "liquid being stored, and a sealing means for the annular space around the p r r d 'i 1 fbq ollfi fi l a' l i ible sealing elementof 'tre'ated fab'ric or other, suitable material, attached to the edge of thereof 7 andtoth e a let 't j oa ha ch a m nne t it will heat su e ded. underside'oiithe roof during the rise ofthe roof. "A liquid storage"apparatu-sfoi' the eneral type or kind abovementioned is disclosed x PatentNo, 2959686, ted Aug One object of 'mj reissst invention is to bro charged from Same into" the loop 'o f thefiex ibl'e sealing element orinto the space between said element and theisidefwall of" the container; during the d'b'wnwardtravel f theroof; ammabile lifluid will b'ereturn d to saidtrough where it will he 'inreadines's'to nerform its function during the s cceeai gupward tlayel' r the rem;

'Another object is to nrovid'e a storage aena atus of the" general kizi'driiht'iqh d,-"th'at equipped with a means rmeenaaism" for pr' ventin excessive bu ging or'belhrin of" the ible' sealing element, inwardly awa rromthe side wall of the con ainer. as a result of nressu efexerted on said element by the mobile liquid con fined in the loo of saia'element or in the space be weenthe sealing element and the side wall ofthe container?- Andstill' another object ofrny'inventfonis to providea storage apparatus of the general kind 7 H Wiggin IH. 'Aptncseph ne a teiai, isasjs nainbps1 6 18 4cla m's (013220-26),

Other objects and'desirable features of my -in-' vention'will'be' hereinafter pointed out. f

Figure 1 of the drawingsfi's a fragmentary verticalt'ransverse sectional iew of a liquid storage apparatus embodying my present invention; showing the floating'roofat thend of its upward stroke, in the position it occupies when the eontainer is full of liquid. v

ing roof in an intermediatejposition between its high and Iow positions aria Figure 3 is a similar viewfshowing the-roofin its lowermost position.

:- In the drawings, A designates the side waIIFof a cqz ntainerjortank; in which liquid X is being stored? and B designate-s a vertically-movablefioa'tingroof ithat rests-upon and ia-sustained :by V

the; liquid X being stored; The-annular: space at the peripheraled'ge of the roof is closed by a flex ib'le-sealing element 6, preferably cons-truetedof treated fabric; attached to therperipheral edgeiof the roof and-do the: intermediate portion: of-c'the side wall. of! the container, ,and'made'ofsuch. shape -.and size that it 'is' calfable ef folding on'dowbiing' -during'thez riseandffal'lof -the roof.

Ini'order to insure: that "the sealing element will assume theiorm of a downward-hanging loop; lzprovide the roof Bat its peripheral edge with portions that constitute the bottom and" one sidewall. of atrough, designated as an entirety by thereference character B, that i'sada-pted to contain a body -=of mobile. liquid; 01; which;

during: the upward jtraveli of theroof, escapes from or, spills out; of said trough Bfaudi -exerts azforce on the sealingelement C that causes said sealing element toassume the shape; or form of a downwardly hanging loop: Said trough' -B' can. be constructed .in various' wayswithout dementioned, that is' equipped with anovel means orrzmechanism for preventin the flexiblesealing element from bulging or; belly-ing outwardly Texcessively and rubbing against the side w-allaetthe container, in instances where'theyliquid stored inthe container exerts outwardv-pressure on said sealing element" in excess of the inward pressure which the mobile liquid exerts on said element.

trough B exertsa downward-for,

parting-from the spirit of my in-Vention In the form of my invention herein illustrated; the roof is provide-dwitnan upwardly-projecting rim: B set some distance inwardly from the edge-oi the roof; so that iti'constitutes one of the vertical side walls of a trough B; whosebottomis formed by the peripheral: portion of the. roof, the scale ing elementfiG being madeof such-length that when the roof is 'in its lowermost position-,1- as shown in. Figure-fiiysaid sealing element iconstitutesthe other vertical side wall: of'th'eatrough B. *At such. times themobilel "d G in the on the-part of v thesealingt element C immediately adjacent theiperipheral edge of the roof and causes it to assume f a downwardl'y-looped' formf, as clearly shown in: Figure 3'.v As the roof moyesupwar'dly,

more and more 01 the mobile liquid C' escapes from the trough B, into the loop of the sealing element C, or into the space between said element and the side wall of the container, with the result that by the time the roof reaches its highest position, as shown in Figure 1, all, or practically all, of the mobile liquid has been discharged from the trough B' and applied to the sealing element C in such a way as to insure that said sealing element will hang suspended from the edge of the roof. During the first" portion of the downward travelof the roof, the portion 0f the side wall A of the container located above the point of attachment of the sealing element C with said side wall, functions asa side wall for the trough B, arranged in opposed relation 7 to the other side wall B oflv said trough, Durdownward movement of the roof continues, more and more of the mobile'liquid returns to said trough, with the result that by the time the roof reaches its lowermost position, all of the mobile liquid 0' is in the trough B in readiness toagain perform its function on the succeeding u wardstroke of the roof. By handlingthe-mobile liquid C in the manner above described, I roduce an inexpensive apparatus, inasmuch as the bottom and one side wall of the trough B are formed by portions of the roof and the other'side wa'l of said reservoir is formed by a flexiblesealng element C, or by the upper portion of the side wallA of the container. v

If the mobile liouidC' is of greater-specific gravity'than the liquid X being stored in: the apparatus, there is a tendency for the flexible sealing element C to bulge inwardly excessively, away: from the Side wall of'the container, due to the weight of the sealing liquid 0', or the inward force said liquid exerts on the sealing element C. Such excessive inward flexing or bellying of the sealing element C produces random wrinkles or folds in same, which a e in-v jurious to said element. In order to overcome this objection, I have provided thefloating'roof B with a means or mechanism that eflectively takes up forces or strains exerted on the sealing element C in a direction tending to cause it to bulge 0r bellv inwardly excessively during the rise and fall of the roof, and when the roof is in its uppermost position, said means or mechanism being of such construct on and arrangement that it accomplishes this highlydesirable result. without subjecting the sealing element to excessive friction or causing said element to wear rapidly,

ered with rubber or some other suitable material, that will prevent injury to the sealing element C when said element contacts with said supporting devices.

When the roof B approaches its lowermost position, shown in Figure 3, the above described barrier or fender collapses into an inactive condition, with the compression members I disposed in stacked relationship on the bottom of the containenthe supporting devices {being sufficiently flexible to permit the members! to pile up, one on top of the other. During the upward travel of the roof, said barrier or fender progressively unfolds-and assumes an active position, or

operative position, wherein it is arranged in such relationship ,with the sealing element C, that pressure exerted by the mob le liquid C on the sealing element C in a direction tending to flex said element inwardly, or towards the center of the container, is taken up or absorbed by the barrier, whereby excessive inward bulging, ballooningor bellying of .the flexible sealing elem nt is efiec: tively-prevented. Moreover, this h ghlydesirable result is accomplished without subjecting the seal ing' element C to excessive friction, inasmuch as the sealing element C travels at the same speed as the fender, or barrier, andat notime has a rubbing action on the fender, caused by relat ve vertical movement between said element, and fender.

In addition to providing the floatin roof B with a barrier or fender. that-rises and falls with the roof. and automatically collapses into, an inactive condition as. the roofapproaches its lowermost position, I prefer to provide the roof with a means for preventing the flexible sealing element C from being forcedoutwardly in -o rubbing contact or enga ement with the side wall. A of the container. 'intheevent the pressure inthespace between the sealing elementC and the side wall of the,container becomes less thant e ou ward force orpressure whichvthe stored liquid X .ex,-.

erts on the sealing element C. .Such areduced,

due to relative vertical movement between said means and the element C. Preferably, the means or mechanism just mentioned is of general construction or character described in my companion application Serial No. 515,613, filed of even date herewith, and consists of a collapsible barrier, fender, or fence suspended fromthe peripheral edge of the floating roof B at a pointbetween the sealing element 0 and the center of the roof, and composed of'a plurality of su erimposed, annular-shaped" compression members I, joined to each other and suspended from the underside of the roof by groups of flexible supporting devices 2. The compression members I can be conveniently formed from metal pipe or tubing, bent to form ring-shaped members of a diameter only slightly less than the diameter of the roofB, and the flexible supporting devices 2' can beformed from strips of suitable flexible material, ortfrom pieces of,chain,,orl cable, covdiminished or mi us pressure might be created on'the external side ofthe sea ing element Got in the space between saidelement and the side wall of the container fromyariousicauses- For exam e. abnormal. evaporation oi-the sea-ling liquid C' mi ht cause the stored linuid X to exert an outward force on the sealingelement C tending to cause said element to rub on the sidewall of the tank. therebvretardingethe upwa d move-1 ment of the roof and subjecting the sealing element C to excessive wear. In'tbe form of my invention herein illustrated the means last=referred to that is used tocontrol or-limit outward flexing of the sealing el ment- C,- consists of one ormore annularshaped tension members 3 suspended by chains orother-suitable flexible devices 4 from the peripheral ed eof the roof B, at a point on'the outside of the'fabric e ement- C. If, during theupward travel of the roof. or when the roofis in its uppermost position, the seali g element C tends to belly outwardly excessively; the tension member or members 3 take up the outward force exerted on the element C; and prevent the same from rubbing against the side Wall of the container.

Having thus described my invention, what'I claim as new an'ddsire 'tQ 's'e'c'ure by Letters 1. Ina liquidstorageapparatus, the combina tion of a container for'holding the liquid-"being stored, a floating roof sustained bythezst'cired liquid, T an annular, flexible, liquid-impervious sealing element attached to the peripheral edge of the roof and to the side wall of the container substantially midway of its height so that in the extreme high and low positions of the roof said element will be distended or stretched in substantially parallel relation to the sid wall of the container and in an intermediate position of the roof said element will form a downwardly hanging loop which is open at its upper end, a body of mobile liquid that is adapted to flow into and out of the loop of said sealing element and into and out of the space between said element and the side wall of the container during the rise and fall of the roof, and a trough that is ada ted to hold said mobile liquid, the bottom and one side wall of said trough being formed by portions of the roof and the opposed side wall of said trough being formed by the flexible sealing element when the roof is at or near its extreme low position and by the side wall portion of the container when the roof is at or near its extreme high position.

2. In a liquid storage apparatus, the combination of a container for holding the liquid being stored, a floating roof sustained by the stored liquid, an annular, flexible, liquid-impervious sealing element attached to the peripheral edge of the roof and to the side wall of the container substantially midway of its height so that in the extreme high and low positions of the roof said element will be distended or stretched in substantially parallel relation to the side wall of the container and in an intermediate position of the roof said element will form a downwardly hanging loop which is open at its upper end, a body of mobile liquid that is adapted to flow into and out of the loop of said sealing element and into and out of the space between said element and the side wall of the container during the rise and fall of the roof, and a trough for holding said mobile liquid when the roof is in its lowermost position, said trough bein formed by said sealing element, by the peripheral portion of the roof, and by an upwardly-projecting part on the roof located adjacent the peripheral edge of the roof.

3. A liquid storage apparatus of the kind described in claim 1, provided with a barrier for preventing excessive bulging of said flexible sealing element, said barrier being composed of a plurality of superimposed, horizontally-disposed, ring-shaped compression members joined to each other and suspended from. the underside of the roof by flexible supporting devices.

4. A liquid storage apparatus of the kind described in claim provided with a verticallycollapsible barrier suspended from the underside of the roof for preventing excessive inward bulg-' ing of said flexible sealing element, said barrier being composed of a plurality of superimposed, horizontally-disposed, ring-shaped compression members, and an independent barrier for restricting excessive outward flexing of said sealing lement, mounted on the roof so as to occupy a position between said sealing element and the side wall of the container during a portion of the cycle of operations of the roof.

JOHN H. WIGGINS. 

